Engineering Problems Caused by the Anisotropic Behaviour of the Rock Mass

Why the future of rock mass classification systems requires revisiting their empirical past

Quarterly Journal of Engineering Geology and Hydrogeology ◽

10.1144/qjegh2021-039 ◽

2021 ◽

pp. qjegh2021-039

Author(s):

Beverly Yang ◽

Amichai Mitelman ◽

Davide Elmo ◽

Doug Stead

Keyword(s):

Rock Mass ◽

Rock Mass Classification ◽

Classification Systems ◽

Empirical Knowledge ◽

Rock Engineering ◽

Geotechnical Data ◽

Use Of Technology ◽

Data Collection Process ◽

Engineering Problems ◽

Mass Classification

Despite recent efforts, digitisation in rock engineering still suffers from the difficulty in standardising and statistically analysing databases that are created by a process of quantification of qualitative assessments. Indeed, neither digitisation nor digitalisation have to date been used to drive changes to the principles upon which, for example, the geotechnical data collection process is founded, some of which have not changed in several decades. There is an empirical knowledge gap which cannot be bridged by the use of technology alone. In this context, this paper presents the results of what the authors call a rediscovery of rock mass classification systems, and a critical review of their definitions and limitations in helping engineers to integrate these methods and digital acquisition systems. This discussion has significant implications for the use of technology as a tool to directly determine rock mass classification ratings and for the application of machine learning to address rock engineering problems.

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Prediction of Landslide Position of Loose Rock Mass at Mountain Tunnel Exit

Advances in Civil Engineering ◽

10.1155/2019/3535606 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9

Author(s):

Ya-Qiong Wang ◽

Cheng-Bin Ma ◽

Zhi-Feng Wang

Keyword(s):

Rock Mass ◽

Prediction Methods ◽

Tunnel Engineering ◽

Improved Method ◽

Engineering Problems ◽

Calculation Results ◽

True Position ◽

Optimal Calculation ◽

Mountain Tunnel ◽

Loose Rock

Landslide of loose rock mass at mountain tunnel exit occurs easily, and prediction of landslide position is one of the engineering problems to be solved urgently. Currently, existing and used prediction methods, such as field monitoring measurement, numerical analysis, nonlinear theories, and the geometric method, play a very important role and have their limitations. For example, there is a bigger difference between calculation mode by Wang et al.’s method and actual engineering situation; besides, there exists a relatively big discrepancy between the predicted and true position. Aiming to solve this problem, this article combined theoretical analysis and actual engineering situation to establish an optimal calculation mode. At the same time, this article re-deduced instability criteria based on the stress-transferring theory and examined the factors that influence solutions. The improved method can predict landslide position more accurately because the parameters (β, s, H, α, γ, c, φ, and T) related to the occurrence of landslide are taken into consideration. It is pointed out that landslide possibly occurs in the case of Δ ≥ 0 and Y ≤ 0. In addition, the equations s1 < s < s2 and 0 ≤ s ≤ H/sin α can determine landslide position accurately. The method is applied to two engineering examples, and the calculation results show that the deviations of predictive position from the actual landslide position are only 0.10% and 0.07%, respectively, indicating that prediction results are accurate and reliable. It is suggested that the proposed method is a useful tool in the design of tunnel engineering.

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